The conditioning of air within commercial aircraft is an important feature of commercial aviation. While an aircraft remains on the ground in the hot sun, the air within the aircraft must be cooled in order to maintain passenger comfort. However, when the aircraft is at altitude (e.g., 30,000 feet), the air outside may be below zero. In this case, the air within the aircraft must be heated.
Because of the extreme conditions under which an aircraft operates, the air conditioning system must be robust and able to operate under great temperature differences. On the other hand, anything within an aircraft must be as small and lightweight as possible in order to reduce fuel costs.
In order to distribute the conditioned air through the aircraft, most aircraft are provided with an adjustable air vent located above each passenger seat. This allows passengers to easily change the flow of air as required to maintain a comfort level acceptable to the passenger.
Because of the adjustable air vents, the most practical location for air conditioning ducting is in the ceiling. However, most aircraft require overhead bins for storing carry-on luggage. As such, the ducting for distributing conditioned air must be located behind or above the bins.
One of the requirements for the properly conditioning the air within an airplane is the proper detection of cabin temperature. However, the cramped nature of the aircraft cabin does not lend itself to the easy use of thermostats or other temperature sensing devices. Because of the importance of commercial aviation and passenger comfort, a need exists for better methods of controlling aircraft cabin temperatures.